Switchboard plug



Dec. 23, 1930. A. P. BI EREGKOFF' 1,735,329

- SWITCHBOARD PLUG Filed Dec. 8, 1922 Fig.2..

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. Inve Anatol E B fal'n Patented Dec. 23, 1930 UNITE S AT S? PATE T OFFICE anaror. r. nnnnexorr, onscHENEcTAnY, NEW YORK, As'srenon 'ro GEN RALELEC TBIC'GOMIANY, A CORPORATION or'rrnw yon'x sWironBoAnn PLUG j Application filed December 8 1922. Serial No. 605,711.;

The present invention relates to connectors for electric conductors, and more especially 7 to switchboard plugsof the telephone typev whereby both sides'of a "branch circuit may vbe connected to or disconnected from the respective sides of a main circuit by merely inserting into or removing from a single narrow hole. in. a-protective board or panel over the main 'circuit conductors and contacts.

As switchboard plugs have heretofore been made, the branch circuit wires could not be connected to or disconnected therefrom without disassemb'ly of parts and the employment of skill in making the proper connections. Moreoven'agreat many instruments and distributmg devices; especially of the wireless communications art,have, their'flex 1ble c1rcu1t wlres provided with terminals or tips which are soldered to the wire ends and extend over and retain the braided insulation inplace, and as these terminals or tips are not adapted for connection to'the head of the usual binding screw of'switchboard plugs, 1t

has been the practice, when connecting to such plugs, to cut off the terminals or tips and wrap the bared flexible conductor about the screw and then turn the latter home, but such cutting off of the tips usually spoils the conductor for connection to anything else. i

The object of my invention is to provide an improved switchboard plugto whichflexible branch circuit 'wires', with or without terminals or tips, mayreadily be connected or disconnected by the unskilled and further to enable one or more branch circuits to be connected to a single plug.

t The accompanymg drawing shows two em I bodiments of my invention, Fig. 1 being a perspective view of a single circuit plug with the flexible conductor tips disconnected therefrom; Fig. 2 s a top plan view of the plug with one-half of the outer shell removed toexpose the interior parts; Fig. 3 is an explug, and Fig. is-a-fragmentary plan View of one of the binding posts with'atipped flexible conductor f connected thereto.

,Referring' to the single circuit plug of Figs. 1,2 and 3, the'recessed body member or insulating shell which serves as a handle as well as a housingfor the current carrying parts hasa square exterior in cross section andis split longitudinallyinto two counterpart sections ,1 vand 2, each cored out on its inner wall to fit closely about the metallic parts housed between them and inthe middle of each section is anarcuate slot 3. A single screw 4 passes transverselythrough the sections and holds them assembled about the intenor structure. V Y The current carrying structure vcomprises the usual plug contacts consisting of a headed metal bolt 5 and a. metal sleeve 6 surrounding the shank of the bolt and insulated therefrom and each of these contacts has rigidly attached to its'inner end a metal bracket'l or 8 which are assembled with their shank portions 9 diagonally disposed on opposite sides" of and parallel ,to the axis, of the plug. The shank portions 9"of the brackets 7 and 8 each has attached to its free end a wire gripcomprising a stationary jaw in the form of a.;U-shaped yoke 10 and a-movable jaw in the form of an eccentric cam 11 pivoted in the yoke with its operative edge adjacent the bottom thereof. The cam 11 is pivoted on a shaft 12 mounted in the yoke 10 adjacent its union with shank 9 and projects slightly beyond the sides thereof, and about these projectingends of the shaft 12 are mounted the coilsl3 of a bent wire spring 14 A having a ,connecting central loop 15 straddling the yoke 10 and cam 11 while the ends of the spring are bent to lie parallel to each other across'the face of the bracket shank 9. The cam 1 1v has a lug 16 bent up from its outer edgeand, when assembled in the insulatingshell, projects into an arcuate slot 3 where it may be readily engaged and "moved by the thumb of the operator against the thrust of the spring 14 to permit a flexible conductor, either with orwithout a tip 17, to be inserted longitudinally between the inner endof theyoke 10 and the edge of the cam 11, and upon release of the lug 16 by the operator the cam moves outwardly under recoil of the spring 14 and grips the inserted conductor end or tip. Any stress exerted on the flexible conductor, tending to withdraw it, merely operates to etl ect a tighter grip of the cam thereon.

In order to insulate the oppositely disposed bracket shanks 9 and the respective wire grips carried thereby, two rectangular strips 18 of sheet fibre with an outer corner 19 removed are disposed between them with the cut away corner of each arranged adjacent the respective wire grip to provide clearance space for the spring let. The insulating shell is provided with cylindrical end recesses 20 in alignment with the respective wire grips and between them is a wire bale 21 with its ends anchored in the holes 22 in the respective shell sections, the purpose of which is to enable a strain cord 23 connected to the flexible wires to be tied thereto.

Referring to the duplex plug of Fig. 4, the insulating shell is oblong in cross section and the sections 1 and 2 are cored out for two sets of cord grips. The plug contacts 5 and 6 are connected to brackets 7 and 8 w"-h shanks 9 lying on the same side c" axial plane of the plug and having their free ends 24 bent inwardly. To these bracket ends 24 two wire grips, such as above described. are connected and disposed on the same side of the axial plane. Two other wire grips are connected to a transverse series connection strip 25 entirely independent of the plug contacts. They are disposed in one of the shell sections 2 and boxed therein by a strip of sheet fibre 18' having two portions 19 cut away opposite the wire grips. The plug contacts 5 and 6, with their connected brackets and wire grips, will be similarly boxed in the other shell section 1 and the whole secured in assembled relation by a screw passing through the holes 26, 27, E28 and 29.

In case it is desired to connect to a switchboard a single branch circuit by means of the duplex plug, the wire tips will be engaged with the two grips connected to the plug contacts 5 and 6, and, in case it is desired to connect two branch circuits thereto, one wire tip of each will be connected to the wire grips connected to the plug contacts and the other wire tip of each circuit will be con nected to the wire grips connected to the series strip 25.

lVhile I have shown and described herein the best embodiments of the invention known to me, I do not desire to be restricted thereto.

What I claim as new and desire to secure by Letters Patent of the United States, is

l. A switchboard plug havin a longitudinally split shell of insulating material cored out for the metallic parts, metallic current carrying brackets respectively connected to plug terminals, sheet insulation disposed between said brackets, common means for holding said shell parts, said brackets and sheet insulation in assembled relation, and wire gripping means secured to said brackets and provided with hand engaging means projecting outside said shell.

2. A switchboard plug having an insulating shell, metallic current carrying brackets mounted in said shell and respectively connected to plug cont-acts, a series connection mounted in said shell independently of said brackets, wire gripping devices connected respectively to said brackets and to the ends of said series connection and provided with hand engaging levers extending to outside of said shell.

3. A switchboard plug having an insulating shell with side slots, metallic current carrying parts mounted. in said shell, and a. wire gripping device attached to said current carrying parts comprising a U-shaped yoke, an eccentric cam pivoted therein and provided with a lug arranged to project through a side slot in said shell.

4. An electric plug of the telephone type, comprising a rod contact portion having a head and a rod like shank, a tubular contact portion surrounding said rod contact portion, a spring pressed connector associated with each (it said contact portions, said connectors beingdiametrically opposed, means for retaining said contact portions and connectors together as a unit, a fiat two-piece insulating handle adapted to partially enclose said unit, and means accessible outside said. handle for releesin Said spring pressed connectors.

55. In an electrical connection, an insulating block provided with recesses to receive wire terminals and with abutments adjacent sides of said recesses to hold said terminals against lateral displacement in one direction, cams pivotally mounted in said block and provided with gripping edges arranged adjacent the opposite sides of said recesses, means to normally urge said cams into ongagement with said terminals. means within said block for electrically insulating said (erminals, one from the other, and means projecting from said block and o 'ieratively associated with said cams to release said cams from engagement with said terminals.

(3. In an electrical connection, an insulating block including two substantially similar sections provided with recesses to receive wire tern'iinals, cams pivotally mounted in said block and provided with gripping edges each capable of engagement with one of said terminals, means associated with each of said cams for normally pressing the gripping edge thereof into engagement with one of said terminals, means within said block for electri cally insulating said terminals one from the other and means projecting from said block and operatively associated with said cams to release said cams from engagement with said terminals.

7. In an electrical connector plug for removably uniting electric conductors to jaw switch contacts, the combination with a recessed body member, of a plug contact carrying post composed of mutually insulated conducting members, and spring pressed connectors, mounted on the post and electrically connected respectively to the said conducting members, each of said connectors comprising a pair of jaws disposed within the recessed body and adapted to be forced apart by the end of an advanced conductor tip, and to clamp said tip against withdrawal, and means operable from the exterior of the casing to release a clamped tip.

In witness whereof, Ihave hereunto setmy hand this 7th day of December, 1922.

ANATOL P. BER'EGKOFF. 

